feat(areabrick-overview): automatic colors for additional properties

[jdreesen]

Currently, only additional properties with name tags and groups are colored.

This PR adds an algorithm that automatically colors any tag depending on its name. This works by hashing the name and converting the resulting hash to an HSL color within a given range (which allows us to only create blueish colors, for example).

Then the luminosity of the background color is determined to decide whether the text should be displayed in white or black.

Currently, only bluish colors are generated (see 3873a6f):

Resolves #25

[mike4git]

I've tried to understand what you did but I'm missing (atm).
So I've asked our Twig expert Steffi to have a look upon it and be impressed or disappointed - let's see ;-)

[nsd0sketzler]

looks good!